Immunohistochemical expression of cyclin-dependent kinase inhibitors p16 and p57 in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a highly malignant cancer and is the most common soft tissue sarcoma in children and adolescents, but it is rare in adults (<1% of all adult malignancies). Altered expression and molecular abnormalities of cell-cycle-regulatory proteins are one of the most prominent features in RMS. Therefore, we evaluated the expression of cyclin-dependent kinase inhibitors p57 and p16, as well as p16 methylation status, along with clinicopathological characteristics and overall survival (OS) in RMS patients. This analysis was conducted on 23 pediatric and 44 adult patients. There was a male predominance in both groups and extremities were the most frequent tumor site. In adults, alveolar and pleomorphic types were almost equally represented. The majority of pediatric tumors were low grade, whereas, in adults, only one patient had a low-grade tumor. Seven pediatric (30.43%) and eight adult (18.18%) patients had a low p16 expression. The analysis of methylation status of the p16 promoter showed the presence of methylated allele only in one sample with pleomorphic histology. Six (26.1%) pediatric and 15 (34.1%) adult patients had low p57 expression, while in 17 (73.9%) pediatric and 29 (65.9%) adult patients it was assessed as high. Ninetyone percent of the pediatric patients and 32.6% of adults were alive at the end of the observational period. In adults, significant associations were found between OS and age (P = 0.020), gender (P = 0.027), tumor size (P < 0.001), lymph node status (P < 0.001), presence of metastases (P = 0.015), and p57 expression (P = 0.039). Stratification by histological type showed the correlation of low p57 expression (P = 0.030) and worse OS of patients with alveolar RMS. Univariate analysis identified age > 50 yrs. (HR 2.447), tumors > 5 cm (HR 21.31), involvement of regional lymph nodes (HR 3.96), the presence of metastases (HR 2.53), and low p57 expression (HR 2.11) as predictors of lower OS. Tumor size, regional lymph nodes involvement, and metastases were the independent predictors after multivariate analysis, while p57 did not predict OS in an independent way. In summary, although p57 was not confirmed to be an independent predictor of OS, our results indicate that its low expression may be the marker of aggressive phenotype and poor prognosis in adult RMS patients. Also, our findings suggest that epigenetic inactivation of p16 is not important in the pathogenesis of rhabdomyosarcoma.

Placental mesenchymal dysplasia in a normal female infant: a rare case report with follow-up

Placental mesenchymal dysplasia (PMD) is a rare disorder of unknown etiology, which is often misdiagnosed as partial hydatidiform mole because of their similarity in ultrasonographic, gross, and histologic presentations. However, the treatment and prognosis of these two conditions are different. Patients with PMD often have intrauterine growth restriction, intrauterine fetal death, and Beckwith-Wiedemann syndrome, but there may also be a normal fetus. PMD with a normal female infant is extremely rare, and only a few cases have been reported. We report a case of PMD in a normal female infant and its follow-up results.

Expression of p57 immunomarker in the classification and differential diagnosis of partial and complete hydatidiform moles

BACKGROUND:

Hydatidiform mole (HM) is characterized histologically by cystic swelling of the chorionic villi, accompanied by variable trophoblastic proliferation. The most important reason for the correct recognition of moles is that they are associated with an increased risk of persistent trophoblastic disease (invasive mole) or choriocarcinoma.

AIMS AND OBJECTIVES:

The aim of the study was to determine whether there is any role of p57 in differentiating partial and complete moles by immunohistochemical staining.

MATERIALS AND METHODS:

A prospective observational study was undertaken in which 40 cases of molar pregnancy included over a period of 2 years. Detailed clinical and family histories were obtained from each patient. Histopathological examination followed by immunohistochemical study with p57 done in each case. Ultrasonography findings and serial titers of serum beta-human chorionic gonadotropin were noted whenever necessary.

RESULTS:

Among the forty cases included, 25 (62%) had complete molar (CM) pregnancy, whereas the rest 15 (38%) had partial mole (PM). Both CM and PM were more pronounced in the age group of 20–25 years (44% and 60%, respectively), and among nulliparous women (68% and 70% respectively), 17 (42.5%) mothers had a prior history of abortion. In the histologically unequivocal cases of complete mole, 96% (24 of 25) did not express p57 and a single case was focal positive. In contrast, it was strongly and continuously expressed in both villous cytotrophoblast and stromal cells in all cases of PM (15 of 15).

CONCLUSION:

p57 immunomarker is very helpful to diagnose and differentiate complete and partial HM.

The importance of immunohistochemistry in the differential diagnosis of molar disease

The differential diagnosis among complete moles, partial moles and hydatidiform abortions may be challenging during routine diagnostic activity. These entities share the histological aspect of enlarged villi, but here we summarize also some peculiar features of all of them. If histology does not clarify this distinction, the immunohistochemistry is the most important tool for pathologists to complete such diagnosis. The correct management of immunohistochemistry and of further possible analysis is also reviewed. Lastly, the most important antibodies, starting from p57, are presented.

P57 and cyclin G1 express differentially in proliferative phase endometrium and early pregnancy decidua

OBJECTIVE

To compare the expression of P57 and Cyclin G1 in proliferation endometrium and early pregnancy decidua.

METHODS

Human endometrial samples were acquired from normal menstrual cycle women undergoing laparoscopy or hysterectomy for fallopian tubes problems. Decidua were acquired from women in early pregnancy who underwent artificial abortion without any endometrial problems. Twelve were in proliferative phase and 13 were deciduas. P57 and Cyclin G1 mRNA and protein were measured by real-time PCR and Western blot.

RESULTS

The expression of P57 mRNA and protein were lower in proliferation phase compared with the early pregnancy decidua. Cyclin G1 mRNA and protein expression were slightly higher in decidua than proliferation endometrium but it had no significant difference.

CONCLUSION

P57 and Cyclin G1 may play an important role in the endometrial change during the embryo implantation.

Lefty inhibits in vitro decidualization by regulating P57 and cyclin D1 expressions

Endometrial decidualization is highly important for successful construction and maintenance of embryo implantation and pregnancy. Lefty gene at different menstrual cycle phases has different expressions, indicating its regulatory significance. To study the mechanism of Lefty in decidualization, human endometrial stromal cells (hESCs) were cultured and induced with medroxyprogesterone acetate (MPA) and 8-bromoadenosine-cAMP (8-Br-cAMP) in vitro as a research model. Our results showed that Lefty1 overexpression inhibited MPA- and 8-Br-cAMP-induced hESC decidualization and significantly reduced the secretion of prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP-1). With the inhibition of Lefty1 expression, hESC decidualization induced by MPA and 8-Br-cAMP became more remarkable, and the secretions of PRL and IGFBP-1 were higher too. Further tests indicated that during the process of decidualization, P57 expression increased, whereas cyclin D1 expression decreased. Although Lefty1 overexpression did not significantly change the expressions of P57 and cyclin D1, inhibition of Lefty1 expression resulted in more evident changes in P57 and cyclin D1 expressions. Meanwhile, cell cycle examination showed that Lefty1 overexpression reduced the cell cycle arrest at G1/S phase in the in vitro hESC decidualization model. Therefore, Lefty1 could regulate the cell cycle via modulating the expressions of P57 and cyclin D1 and then inhibit the decidualization in vitro.

Hoodia gordonii extract targets both adipose and muscle tissue to achieve weight loss in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Hoodia gordonii (Masson) Sweet ex Decne (family Apocynaceae) is consumed globally as a natural appetite suppressant. While this effect-and its subsequent effect of weight loss-has been reported in the scientific literature, no information is available on the specific tissue types affected that accounts for the significant weight loss reported after consumption of the plant. Furthermore, most studies are performed on lean animals, so that the response of overweight or obese individuals to this plant supplement remains largely unknown.

MATERIALS AND METHODS

Twelve lean and twelve obese male Wistar rats were supplemented with different doses of Hoodia gordonii extract (80 or 160 mg/kg body mass twice daily) in a placebo-controlled study, for a period of 14 days.

RESULTS

All supplemented rats exhibited significant weight loss (P<0.001). This could be ascribed to decrease in both adipose cell size and skeletal muscle fibre size.

CONCLUSIONS

We conclude that the weight loss seen after consumption of Hoodia gordonii is due to loss of both adipose and muscle mass.